Background:Ex vivo lung perfusion (EVLP) supports assessment and rehabilitation of donor lungs. It runs as a closed circuit, so electrolytes and metabolites accumulate over the duration of perfusion. This systematic review investigates the impact of various dialysis or perfusate exchange (PE) techniques on electrolyte balance, inflammation and lung function during EVLP. Methods:A literature search of PubMed and Embase was conducted from database inception to September 17, 2025. We included all articles describing human or animal studies that tested dialysis or PE during EVLP. Outcomes included electrolytes, lactate, pH, edema formation, lung performance characteristics, and inflammatory markers. Results:Five studies met the inclusion criteria, one human and four porcine models, with a total of 57 subjects. Across studies, dialysis consistently improved solute clearance, lowering sodium, potassium, and chloride, while increasing calcium and glucose, reducing lactate accumulation, and maintaining physiologic pH. PE did not sustain physiologic pH and had limited impact on electrolyte homeostasis, with only transient effects on lactate. No differences were observed in lung function parameters including oxygenation, compliance, and airway pressure. Pro-inflammatory cytokine production was largely unchanged, however, interleukin (IL)-10 was elevated with dialysis in several studies. Conclusion:During EVLP, dialysis stabilized acid-base status and metabolites. These biochemical gains did not translate into consistent improvements in oxygenation or compliance. Smaller dialysis membranes were associated with higher pulmonary artery pressure (PAP) and increased cytokine profile. Future studies should extend EVLP duration with perfusate clearance to evaluate whether perfusate clearance strategies provide additional benefits with longer duration preservation.

Background Ex-situ heart perfusion (ESHP) improves donor heart preservation via provision of a semi-physiologic, controlled environment. Optimizing preservation capacity through ESHP is of great interest to expand the donor pool and overcome logistical challenges. However, devices are currently untailored to pediatric donor hearts. We sought to evaluate subnormothermic ESHP (sESPH) in comparison to static cold storage (SCS). Methods Juvenile Yorkshire pig hearts (∼20 kg) were procured and subject to 10 hours of sESHP (n = 6) or 6 hours of SCS in modified Del Nido solution (n = 5), then transplanted orthotopically into weight-matched recipients. Following 2 hours of reperfusion, echocardiography was conducted before pigs were euthanized and samples of the ventricles were collected for analysis. Immunofluorescence staining for vascular inflammation markers VCAM-1, ICAM-1, and E-selectin was conducted. Hematoxylin and eosin staining of the ventricles was conducted and reviewed by a pathologist blinded to the experimental groups and scored for contraction bands, edema formation, inflammation, and hemorrhage. Results By echocardiography, hearts from both groups regained acceptable biventricular functionality, with no difference in left ventricular ejection fraction and shortening fraction between groups (p > 0.05). No differences in histological damage scores were found between groups (p > 0.05). Immunofluorescence staining showed qualitatively lessened expression of all markers in the sESPH group. Conclusions sESPH appears to prolong out-of-body time of pediatric donor hearts, with non-inferior tissue and functional preservation compared to SCS. sESHP may lessen inflammatory burden over the course of the preservation period.

Background:Ex-situ heart perfusion (ESHP) enables improved donor heart preservation, yet still suffers functional decline. The perfusate is 1 area that requires optimization, especially with regard to hemoglobin (Hb) content. We sought to compare performance of concentrated, physiologic, and dilute perfusates in minimally damaged hearts. Methods:Hearts of juvenile Yorkshire pigs (45-55 kg) were procured and subject to 11 h of working-mode ESHP in 1 of 4 groups varying in Hb: concentrated blood (CB, ~12 g/dL Hb, n = 4), whole blood (WB, ~8g/dL Hb, n = 6), plasma (~4g/dL Hb, n = 6, diluted with donor plasma), and control (~4g/dL Hb, n = 5, diluted with modified Krebs-Heinseleit). Functional, metabolic, and hemolytic markers were recorded and compared between groups statistically using appropriate statistical tests. Results:CB hearts exhibited worsened decline from baseline in cardiac index, dP/dT max/min, and stroke work (P < 0.05) and had greater elevations in hemolytic markers by end perfusion. Preservation of baseline cardiac index did not differ significantly between controls, WB, or plasma groups over time (P > 0.05). The CB group displayed elevated early oxygen consumption compared with controls (P < 0.05), with WB and plasma groups trending toward increased oxygen consumption. Lactate elevated over time in all groups, however, was not comparatively elevated within the CB group; it was reduced in the plasma group during early perfusion compared with control. Conclusions:Hb dilution appears to lower absolute output but preserves baseline function. Supraphysiologic Hb elevation or sublethal blood cell damage exacerbates hemolysis, which contributes to functional decline during ESHP. Lactate evolution did not appear to associate with the degree of functional loss.

BACKGROUND:Prolonged mechanical ventilation increases the risk of developing ventilator-induced lung injury, but the relationship between the duration of donor ventilation (DDV) and post-lung transplant lung function is unknown. METHODS:We analyzed adult patients undergoing double lung transplantation in our program between January 2007 and December 2020. The risk factor of interest was DDV in days before organ retrieval. The primary outcome was forced expiratory volume in 1 s % predicted at 1-y posttransplant (1yFEV1%), and secondary outcomes, including lung function at 3 mo, short and long-term graft dysfunction, and mortality, were tested. We used multivariable linear regression to test the association between DDV and 1yFEV1%, adjusting for variables known to be associated with posttransplant lung function. RESULTS:Seven hundred fourteen patients were eligible for the study, 588 of whom had available DDV data. Median DDV was 3 d (range, 0-37 d). In the multivariable analysis, longer DDV was not associated with a lower 1yFEV1% ( P  = 0.897) or other secondary adverse outcomes. DDV was however significantly associated with donor bronchoalveolar lavage culture positivity for clinically relevant organisms (odds ratio, 1.11 per day of ventilation; 95% confidence interval, 1.02-1.21; P  = 0.02). CONCLUSIONS:DDV before procurement was not associated with 1yFEV1% or other secondary adverse outcomes. This may relate to a lower risk of ventilator-induced lung injury and its long-term effects in acceptable lungs that otherwise meet criteria for donation. This suggests acceptable donors with extended ventilation duration before offer can be safely considered for lung transplantation.

Background:Von Willebrand factor (VWF) is a procoagulant glycoprotein expressed exclusively in endothelial cells and megakaryocytes. It mediates platelet adhesion to endothelial/subendothelial surfaces and initiates thrombogenesis. External stimuli, including hypoxia, were shown to upregulate VWF expression levels and alter its vascular tree expression pattern in the lung. Increased VWF levels are a significant risk factor for thrombus formation, a major complication in organ transplantation. Given that donor organs experience hypoxic conditions during transplantation, this study investigates whether hypoxia alters VWF expression and whether modifying organ preservation to reduce hypoxic exposure could prevent these alterations. Methods:Porcine procured lungs were maintained in either static cold storage (SCS) or ex vivo lung perfusion with warm perfusion. Lung tissue biopsies were obtained immediately after organ procurement, 12 h post-cold storage, or post-warm perfusion. VWF RNA and protein expression levels and patterns were analyzed using reverse transcriptase-polymerase chain reaction, Western blot, and immunofluorescence. Results:Immunofluorescent analysis demonstrated that transplanted lungs maintained under SCS, but not ex vivo lung perfusion, exhibited VWF expression in an increasing number of microvascular endothelial cells, whereas warm perfusion led to a significant reduction in VWF mRNA levels, and it also showed a clear trend toward reduced protein expression compared with cold storage. Conclusions:Increased VWF expression in microvascular endothelial cells under SCS may contribute to transplant-associated thrombogenicity. Decreasing VWF expression through ex vivo normothermic perfusion could significantly mitigate the risk of thrombogenic complications, a major complication of organ transplantation.

Background:. Coronary artery disease (CAD) and ischemic mitral regurgitation (IMR) commonly co-exist, yet the optimal intervention for these patients is unclear. Herein, we perform a systematic review and meta-analysis comparing the outcomes of patients with multivessel CAD and IMR undergoing coronary artery bypass grafting (CABG) or percutaneous coronary intervention (PCI). Methods:. PubMed and Embase were systematically searched for articles comparing outcomes of patients with CAD and IMR undergoing revascularization with CABG or PCI, with or without concomitant mitral valve interventions. Thousand two hundred eighty-five studies were identified and 8 were included in this review after full text review. The primary outcome of this study was mortality, and secondary outcomes included myocardial infarction, stroke, heart failure hospitalizations, and residual or recurrent mitral regurgitation. Results:. Pooled analyses identified no significant differences in long-term mortality [odds ratio (OR): 1.13, 95% confidence interval (CI): 0.77–1.68, P = 0.53] with considerable heterogeneity between studies. However, following the exclusion of a single outlier, heterogeneity in the pooled analysis of long-term mortality improved and the outcome favored CABG over PCI (OR: 1.39, 95% CI: 1.06–1.83, P = 0.02). Rehospitalization for heart failure also favored CABG (OR: 1.49, 95% CI: 1.16–1.92, P = 0.002). Conclusion:. This systematic review and meta-analysis suggested lower rates of long-term mortality and heart failure hospitalizations for CABG compared to PCI. CABG remains preferrable for patients with acceptable surgical risk, multivessel CAD, and IMR.

Extending the storage of donated livers beyond the current 4-6 h via freezing could significantly improve transplant availability. However, mitigating freezing injury in complex organs remains challenging because conventional cryoprotective agents (CPAs) are difficult to perfuse uniformly and several biologically important injury mechanisms are not well controlled. Ice recrystallization, where larger ice crystals grow at the expense of smaller ones, is one such mechanism. To address this, we evaluated two ice recrystallization inhibitors (IRIs), N-(2-fluorophenyl)-C6-azido-D-gluconamide (2FA) and N-(2-chlorophenyl)-D-gluconamide (4CLA), for hepatocompatibility and tissue permeation during a 4 h portal vein perfusion of rat livers. Hepatic function assessments showed no general toxicity for either IRI. However, 4CLA-perfused livers exhibited biliary stasis and lacked bile production. Conversely, 2FA maintained bile production and, in post-perfusion biopsies subjected to freezing, successfully reduced ice crystal growth within 200 μm of portal venules. These findings demonstrate that 2FA is a highly promising candidate for supporting long-term liver preservation in the frozen state.

Background:Lung transplant outcomes remain inferior to other solid organ transplants, but there is substantial heterogeneity. Some of this may relate to variations in clinical practice, but the degree to which this variability exists in Canada is not known. We sought to quantify the average practice and the variance among Canadian lung transplant physicians and surgeons via a national survey. Methods:We conducted a digital survey of all physicians and surgeons in all Canadian lung transplant centers, including surgical centers (which perform transplants and provide care pre- and posttransplant) and nonsurgical centers (which provide care pre- and posttransplant). We reported overall averages and results stratified by center. Variability across centers was expressed as Pearson chi-square tests or ANOVA, whereas within-center variability was expressed as percentages and interquartile ranges. Results:We identified 55 clinicians across Canada, of whom 44 (80%) completed the survey, including 31 physicians and 13 surgeons. Respondents were predominantly men (64%), of age 40-49 y (36%), and in practice for 5-15 y (47%). We found the most substantial variability between centers in infection prophylaxis (63%), immunosuppression/rejection management (59%), surgical and perioperative care, and candidate selection. Significant practice variability was also noted within centers. Conclusions:This is the first portrait of average Canadian lung transplant practice and how these differ within and between centers. These differences may affect access to transplantation as well as posttransplant outcomes, and discussions about care standardization based on the best available evidence via existing national bodies would be worthwhile.

Background Coronary artery bypass grafting (CABG) and percutaneous coronary intervention (PCI) are the 2 revascularization modalities for patients with severe coronary artery disease. While CABG has often demonstrated benefits over PCI in multivessel coronary artery disease, analyses of cost effectiveness have previously shown conflicting results and are limited by sample size, follow‐up time, and lack of contemporary data. Methods We performed an analysis of resource use following elective, urgent, or emergent PCI or CABG from January 1, 2009, to December 31, 2018, with up to 14 years of follow‐up. A provincial database was used to collect the associated data. The average cost for each event was calculated from Canadian Institute of Health Information data and was adjusted for inflation on the basis of the Bank of Canada consumer price index. Cost for each group was calculated for readmission to the hospital and repeat revascularization. Secondary outcomes included rates of death, myocardial infarction, rehospitalization, and repeat revascularization. Results Of 23 243 patients who underwent angiography, 7359 were included in this study. Overall costs and costs per patient were significantly higher following PCI compared with CABG. Patients who underwent PCI required $19 165 per person in inflation‐adjusted health care resource costs compared with $12 612 for CABG. Furthermore, patients who underwent PCI had higher rates of death, myocardial infarction, rehospitalization, and repeat revascularization (P<0.001). Conclusions Patients with multivessel coronary artery disease experience fewer adverse events and use fewer health care resources after discharge following CABG compared with PCI. Appropriate selection of CABG versus PCI may help reduce readmissions and health care costs following revascularization.

BACKGROUND:Emergency re-sternotomy after cardiac surgery is a rare but high-stakes event that requires rapid, organized intervention, yet standardized cart designs to facilitate this process are lacking. METHODS:A simplified, numerically organized emergency re-sternotomy cart was developed on the basis of multidisciplinary stakeholder input and evaluated through simulation comparing it with the existing cart design. RESULTS:Simulation results demonstrated improved user satisfaction and a reduction in time to sternal retractor placement-from 280 seconds with the original cart to 57 seconds with the new cart. CONCLUSIONS:This user-friendly and cost-effective emergency re-sternotomy cart design offers a reproducible framework that may enhance efficiency and promote national standardization for emergency re-sternotomies.

BACKGROUND:Substance use is common among lung transplant donors, but concerns persist about graft damage. Stimulant drugs such as cocaine and methamphetamine can induce pulmonary arterial hypertension, while smoked products such as cannabis and crack cocaine can produce airway and parenchymal diseases. We sought to characterize donor substance use at our center and evaluate the associations with recipient survival as well as chronic lung allograft dysfunction (CLAD), severe primary graft dysfunction (PGD3), and baseline lung allograft dysfunction (BLAD). METHODS:We studied patients with double lung transplants in our program between 2004 and 2016, including a history of donor substance use with nine pre-specified agents. We modeled the association with time to death or retransplant, CLAD, severe PGD, and BLAD. RESULTS:Of 473 recipients, 186 (39%) received lungs from a donor with a history of substance use with at least one of the pre-specified substances. There was no overall relationship between donor substance use and any outcome. Heavy donor smoking was associated with an increased risk of death or retransplant (hazard ratio 1.47; p = 0.032), PGD3 (odds ratio [OR]: 2.13; p = 0.014), and BLAD (OR 2.56; p < 0.001). Donor crack cocaine use (n = 24) was also associated with worse survival (HR 2.16; 95% CI 1.16-3.66; p = 0.017) but not CLAD or BLAD. We noted no CLAD associations with any drug. CONCLUSION:A history of donor substance use was common and in general not associated with worse outcomes, aside from heavy donor smoking. These findings may have implications for allocation and post-transplant graft dysfunction.

ABSTRACTIntroductionPreclinically, 24‐hour continuous Ex‐Situ Lung Perfusion (ESLP) is the longest duration achieved in large animal models and rejected human lungs. Here, we present our 36‐hour Negative Pressure Ventilation (NPV)‐ESLP protocol applied to porcine and rejected human lungs.MethodsFive sets of donor domestic pig lungs (45‐55 kg) underwent 36‐hour NPV‐ESLP. Two sets of clinically rejected human lungs were preserved on 36‐hour NPV‐ESLP. Graft function was assessed via physiologic parameters, edema formation, and cytokine profiles.ResultsPorcine and human lung function was stable with mean partial pressure of oxygen divided by the fraction of inspired oxygen (PaO2/FiO2; PF) ratios throughout preservation of 473±11.79 and 554.7±13.26, respectively (mean±standard error of the mean). In porcine lungs, mean compliance (Cdyn) during ESLP was 33.96±2.18, pulmonary artery pressure (PAP) 13.03±0.53, and pulmonary vascular resistance (PVR) 481.20 ±21.86. In human lungs, mean Cdyn was 82.68±3.54, PAP 6.00±0.33, and PVR 184.00±9.71. Average percentage weight‐gain was 34.47±13.22 in porcine lungs and 116.3±6.65 in rejected human lungs.ConclusionNPV‐ESLP can preserve porcine lungs and human lungs for 36‐hours with acceptable physiologic function. Greater weight‐gain in the human lungs is likely due to prolonged ischemic time prior to ESLP and use of an acellular perfusate. Continuous 36‐hour NPV‐ESLP could support therapies for endothelial protection and mitigate fluid accumulation.

Coronary artery bypass grafting(CABG) has long been the preferred treatment for left main coronary artery disease(LMCAD), although percutaneous coronary intervention(PCI) has been increasingly utilized. Despite numerous investigations seeking to identify the optimal revascularization strategy for LMCAD, limitations in sample size or follow-up duration have hindered definitive conclusions. Herein, we compare the long-term outcomes up to 14 years after CABG or PCI for patients with LMCAD. Data was retrospectively collected from a provincial database. The inclusion criteria is patients ≥18 years old, with LMCAD, and revascularization with CABG or PCI. The primary outcome is all-cause mortality. Secondary outcomes are any rehospitalization, myocardial infarction (MI), stroke, or repeat revascularization. Outcomes are adjusted for age, sex, and clinical comorbidities. The average age of the patients was 67 ± 9 years for the CABG patients and 71 ± 11 years for the PCI patients. 84.7

Background. Ischemia/reperfusion injury after lung transplantation is a significant cause of morbidity. In the realm of ex vivo lung perfusion (EVLP), inflammation, edema formation, and reduced compliance have limited the durability of EVLP. Previous evidence has suggested that platelet activation and thrombosis may play a role in both conditions. Methods. A literature search of PubMed and Embase was conducted, including all articles describing all human or animal investigations of platelet activation or the use of antiplatelet agents in the settings of EVLP or lung transplantation. Articles published from database inception to July 15, 2024, were analyzed. Results. In total, 9 studies were included in the review. Studies on EVLP have found an association between platelet activation and adverse effects on lung function, whereas in lung transplantation, platelet activation appears to play a role in primary graft dysfunction. In both settings, the inhibition of platelets ameliorated these effects. Conclusions. Platelet activation in EVLP and lung transplantation results in distal arterial thrombosis and has been associated with graft dysfunction. The use of antiplatelet agents in the included studies was associated with reduced lung injury and improved lung function on EVLP or during lung transplantation.

Background:Ex-situ heart perfusion (ESHP) has been proposed as an optimal method for preserving donated hearts prior to transplantation. Hypothermic oxygenated perfusion (HOP) is a simple method from a device design perspective, with enhanced safety compared to normothermic perfusion in the event of device failure. However, the optimal temperature for cardiac HOP has yet to be determined. We evaluated the effectiveness of 12-hour HOP using University of Wisconsin Machine Perfusion Solution (UWMPS) in different temperatures compared to static cold storage (SCS) for 6 hours followed by simulated transplantation. Additionally, we sought to determine the impact of oxygen supplementation in hypothermic ESHP in the heart function preservation. Methods:Hearts were procured from Yorkshire pigs (n = 35) randomized into 3 preservation therapies: 6 hours-SCS; 12 hours-HOP and 12 hours hypothermic non-oxygenated perfusion (HNOP-without oxygen supplementation). For either HOP or HNOP groups, 3 temperatures were tested (5°C; 10°C; 15°C). After the preservation period, hearts had their function assessed in a normothermic perfusion machine capable of working mode, simulating transplantation. Results:All perfusion parameters were stable throughout (mean ± SD): aortic flow 65 ± 5.57 ml/min, aortic pressure: 11.51 ± 3.17 mm Hg. All HOP hearts presented a better cardiac index than SCS (p < 0.05). The HNOP hearts presented similar cardiac function results compared to SCS. Conclusions:HOP for 12 hours had better heart function preservation than SCS for 6 hours. Even HNOP had similar results compared to SCS. Greater edema formation in ESHP hearts did not affect heart function. Hypothermic ESHP safely enhances function preservation compared to SCS.

BACKGROUND:En bloc heart-lung transplantation (HLTx) has been utilized for the past 50 years for the treatment of end-stage heart and lung disease, with significant evolution in the field over that time. This is a systematic review of HLTx and a description of the evolution and outcomes in this patient population. METHODS:Pubmed and Embase were searched for all articles on HLTx from the time of database inception. A total of 1513 articles were screened, and after exclusion, 29 were included in this systematic review. RESULTS:Reported cases of HLTx were more common in the early era (before 2000), for the indications of cystic fibrosis, Eisenmenger's syndrome, and pulmonary hypertension. In the contemporary era (2000-present), patients were not as commonly transplanted for cystic fibrosis, with pulmonary hypertension and congenital heart disease comprising the majority of cases. Rates of short-term mortality tended to be lower in more recent studies, with only recent studies reporting long-term survival. DISCUSSION:HLTx has evolved substantially. In tandem with isolated heart and lung transplantation, the indications for transplant, medical therapy, and outcomes have changed over time. While HLTx is used less frequently in contemporary times compared to the early days of cardiothoracic transplantation, indications for HLTx continue to exist, and the use of HLTx will continue to be indicated. Centers with experience in HLTx should continue to report trends in patient management and outcomes, to continue to guide continued refinement in the field of HLTx.

Background Coronary artery bypass grafting (CABG) has been associated with reduced mortality, myocardial infarction, and repeat revascularization compared with percutaneous coronary intervention (PCI) for patients with 3‐vessel coronary artery disease (CAD) and diabetes. The majority of previous studies have been limited to follow‐up of <10 years. Herein, we compared CABG and PCI in patients with 3‐vessel coronary artery disease and diabetes with a maximum long‐term follow‐up of 14 years. Methods Patients with diabetes and 3‐vessel coronary artery disease but without ST‐segment–elevation myocardial infarction who underwent coronary angiography followed by CABG or PCI from 2009 to 2018 were included in this study. The primary outcome was mortality, and the secondary outcomes included myocardial infarction, stroke, or repeat revascularization. Outcomes were adjusted for age, sex, and clinical comorbidities. Results A total of 1210 patients underwent PCI (median follow‐up, 9.1 years) while 477 underwent CABG (median follow‐up, 8.1 years). Patients who underwent CABG were less likely to experience mortality (49.6% versus 57.6%, P=0.003, adjusted hazard ratio [aHR], 0.75 [95% CI, 0.61–0.91]), myocardial infarction (15.6% versus 28.1%, P<0.001, aHR, 0.45 [95% CI, 0.33–0.61]), or require repeat revascularization (7.7% versus 26.9%, P<0.001, aHR, 0.21 [95% CI, 0.14–0.30]) at longest follow‐up. Risk of rehospitalization (82.6% versus 83.4%, P=0.656) and stroke (11.6% versus 12.2%, P=0.794) did not significantly differ between groups. Conclusions In this study, we describe one of the longest follow‐up periods for patients with diabetes and 3‐vessel coronary artery disease who underwent CABG or PCI and confirmed that the shorter‐term benefits seen in randomized trials do translate into longer‐term reductions in risk of death, myocardial infarction, or repeat revascularization.

Background. Baseline lung allograft dysfunction (BLAD) after lung transplant is associated with an increased risk of dying, but the association with health-related quality of life (HRQL) and exercise capacity is not known. We hypothesized that BLAD would be associated with reduced HRQL and 6-min walk distance (6MWD) at 1 y post–lung transplant. Methods. We analyzed patients who underwent lung transplants in our program from 2004 to 2018 who completed 1-y 36-item Short Form (SF-36) questionnaire and 6MWD testing. We secondarily analyzed the Beck Depression Inventory and Borg dyspnea scores in patients using the available data. We defined BLAD as a failure of both forced expiratory volume in 1 s and forced vital capacity to reach ≥80% predicted of a healthy reference population’s lung function on 2 consecutive tests ≥3 wk apart at any time point posttransplant. We tested the relationship between BLAD status and SF-36 physical component summaries and 6MWD using least squares regression, adjusting for age at transplant, sex at birth, and primary lung disease. Results. Two hundred sixty-four patients were included, 96 (36%) of whom met the criteria for BLAD. Patients with interstitial lung disease as an indication for transplant and those who received older, female, and heavy smoking donors were at increased risk of BLAD. SF-36 physical component summary scores were lower in patients with BLAD (75 versus 85; P = 0.0076), as were 6MWD values (528 versus 572 m; P = 0.0053). BLAD was associated with lower SF-36 scores (P = 0.0025) and 6MWD (P = 0.0008) in adjusted regression models at 1 y posttransplant. We did not observe differences in Beck Depression Inventory or Borg scores. Conclusions. BLAD was associated with reduced HRQL and 6MWD scores at 1 y posttransplant in adjusted models. This suggests that poor posttransplant lung function could contribute to lower HRQL and exercise capacity in lung recipients and is worthy of further exploration in terms of causes, prevention, and treatment.

BACKGROUND:Aortic valve disease(AVD) accounts for 33 % of valvular heart disease(VHD) but causes over 60 % of VHD mortality. For surgical AVR, mechanical valves are recommended for patients <50 years old and bioprosthetic valves for those >70 years old. OBJECTIVES:To investigate the long-term differences following AV replacement(AVR) comparing bioprosthetic and mechanical valves in patients aged 50-70. METHODS:4,927 patients underwent AVR, 744 of which were propensity-matched 2:1 for bioprosthetic and mechanical valves. Outcomes included mortality, morbidity, and rates of reoperation. RESULTS:The average age of the propensity-matched groups was 57 and 56.7 years, and female sex accounted for 26.4 % and 25.0 % for the bioprosthetic and mechanical valve groups, respectively. Other baseline demographics and comorbidities were similar between the groups. There were no deaths at 30 days and complication rates did not differ between groups(p > 0.05). Mortality at 1, 5, and 15 years was similar between groups. Reoperation rates at 5 and 10 years did not significantly differ between bioprosthetic and mechanical valves(p = 0.84, p = 0.31), although at 15-year follow-up, patients with bioprosthetic valves were more likely to require reoperation(21.2 % versus 9.7 %, adjusted hazard ratio 3.65, 95 % confidence interval 1.07-12.5, p = 0.0.39). CONCLUSIONS:Patients receiving AVR from 50 to 70 years old have similar long-term outcomes irrespective of whether they received bioprosthetic or mechanical valves, with only reoperation being significantly different at 15 years follow-up. With low rates of reoperation, mortality, and avoidance of anticoagulation, bioprosthetic valves are a reasonable option for patients 50-70 years old, although mechanical valves still provide a durability benefit for young patients.